Apparatus for producing photographic pictures.



J. E. THORNTON. APPARATUS FOR PRODUCING P RAPHIC PICTURES.

HOTOG FEB. 1,

APPLICATION FILED Patehted Apr. 24,1917.

INVENTOR. Y JOHl/EDIYAKD THUR/1T0. I flmw/wrw A TTOIFA/E),

STATES PATENT OFFICE.

JOHN EDWARD THORNTON, OF ROCHESTER, NEW YORK, ASSIGNOR TO JOHN OWDENO'BRIEN, OF MANCHESTER, ENGLAND.

APPARATUS FOR PRODUCING PHOTOGRAPHIC PICTURES.

Specification of Letters Patent.

Patented Apr. 24, 1917.

Application filed February 1, 1913. Serial No. 745,725.

To all whom it may concern:

Be it known that I, JOHN EDWARD THORN- TON, a British subject, residingat Rochester,

New York, United States of America, have invented certain new and usefulImprovements in Apparatus for Producing Photographic Pictures, of whichthe following is a specification.

The invention relates to apparatus for printing long strips of filmssuch as are employed for cinematograph or motion pictures.

It is designed to provide such a machine as will print a' long strip ortape with a series of pictures from a negative at a sufficiently rapidrate to be commercially useful where the sensitive surface is of veryslow printing value such as when sensitized without silver salts.

Hitherto these cinematograph pictures have been produced by means ofrapid emulsions containing silver salts, one picture at an impression,and none of the machines generally used for such purposes would becommercially useful for material sensitized without silver, as theycould never turn out enough to pay, on account of the long exposurenecessary for every picture.

Machines for photographic copying or printing have been made with arotary translucent cylinder, an endless flexible translucent blanket tocarry negatives and a ring of incandescent electric lamps both in theinterior and around the exterior of the cylinder but such machines arenot capable of printing cinematograph films without burning ordestroying the celluloid film.

The invention consists essentially of a printing machine constructedwith a drum preferably with a peripheral groove to guide the film, anelastic pad around the periphery of the groove on which the printstriprests, a translucent pressure band encircling the drum and within thegroove and lamps of high actinic and low heating power such as mercuryvapor lamps placed lengthwise around the periphery producing acontinuous narrow streak of light whereby a long length of a sensitizedfilm strip may be exposed in contact with an equal length of negativestrip, the twostrips moving simultaneously forward under the printinglamps, and being kept in perfect contact and accurate register duringthe entire period of such contact.

The invention will be fully described with reference to the accompanyingdrawings.

Figure 1 is a sectional elevation of printmg machine. Fig. 2 is atransverse section of printing drum. I

The machine is constructed with a narrow drum A. of large diameter (sayfrom 7 to 20 feet in diameter) mounted to rotate in suitable bearingsupon a frame (not shown) and driven by an electric or other motor.

The periphery of the drum which may be 3" to 4 wide is preferably formedwith a groove a around the periphery of which is placed a pad or cushiona. of any suitable yielding material such as velvet or plush, apneumatic tube, a rubber strip with or without pegs, or a pad supportedby springs.

Around the drum A to enter the groove a is passed a band B oftransparent material preferably endless and with opaque edges-- such ascelluloid, cellulose acetate, gelatin, combination of such, or the like.The band B passes around about three-fourths of the drums circumference,then leaves it, and is passed back over guide rolls 6. It is kept inconstant tension by a weighted tension roller bv or equivalentmechanism. The width of this band is such that it exactly fits in thegroove in the drum, and owing to its state of tension, maintainspressure contact with the pad or cushion a" at the bottom of the groove.

Around the periphery of the drum A a series of powerful lights C of highactinic power and very low heating power are placed, the lamps I preferbeing Cooper- Hewitt mercury vapor tubes, which are placed end to endlengthwise so that the drum A is encircled, for about three-fourths ofits circumference, by a streak of light about the same width as the filmto be printed.

Outside these again may be placed, if desired, a casing D to inclose theentire apparatus and through the peripherical chamber thus formed may bepassed a strong current of cool air, obtained byforcing the air in froma pressure fan, or drawing it through by an exhaust fan through a pipe(1.

to form an endless band. This is then passed over idle rolls so that itmay rotate and repeat continuously while the sensitive strip I movesconstantly forward.

The drum A is preferably open in the center as shown with spokes.

In operation, when the machine is started the sensitive strip I* and thenegative film Gr are placed face to face and led around the periphery ofthe drum between the pad or cushion a on'the periphery and thetransparent pressure band B. The pressure of the band B holding thefilms F and G tightly against the cushion a maintains them in perfectcontact as they are carried forward the sensitive strip being printed bythe light passing through the negative, the two films entering andleaving the machine at that point where there are neither lights norpressure belt.

A machine of this construction, having a drum of ten to 20 feetdiameter, will turn out a large quantity of film per hour, Withoutattention.

What I claim as my invention and desire to protect by Letters Patentis 1. In an apparatus of the class described, the combination with arotating member having a peripheral groove, a cushion Within the groovefor supporting a sensitized film, a negative film encircling the member,and transparent device encircling the negative film, of an elongatedsource of light partially encircling the device.

2. In an apparatus of the class described, the combination with arotating member, an endless friction member encircling the rotatingmember, a guide for a sensitized film encircling the member, a negativefilm, a transparent device engaging the negative film, and means "forpreventing lateral movement of film, an elongated source of lightpartially encircling the device, and means for removing the heat of thelight.

3. In an apparatus of the class described,

eases? 4. In an apparatus of the class described,

the combination With a rotating member adapted to carry a sensitizedstrip, a developed photographic strip encircling the member, a pressureband partially encircling the member, and means for imparting tension tothe band.

5. In an apparatus of the class described, the combination with arotating member adapted to carry a sensitized strip, a developedphotographic strip encircling the member, a transparent pressure bandpartially encircling the member, and means for imparting tension to theband.

6. In an apparatus of the class described, the combination with arotating member adapted to carry a sensitized strip, a developedphotographic strip encircling the member, an endless pressure bandpartially encircling the member, and means for imparting tension to theband.

7. In an apparatus of the class described, the combination with arotating member adapted to carry a sensitized strip, a developedphotographic strip encircling the member, an endless transparentpressure band partially encircling the member, and means for impartingtension to the band.

In testimony whereof I have hereunto set my hand in presence of tWosubscribing Witnesses. 7

JOHN EDWARD THORNTON.

Witnesses:

J. OWDEN OBnmn, GEO. I-I. QBnmn.

